Compressor or the like



Jan. 28, 1930. P. K. LINDSAY COMPRESSOR OR THE LIKE 2 Sheets-Sheet 1Filed Nov. 17, 1927 I 171L367: i0)" 1 fyfliimsa Jan. 28, 1930. P. K.LINDSAY COMPRESSOR OR THE LIKE Filed Nov. 17, 1927 2 Sheets-Sheet 2Patented Jan. 28, 1930 PATENT OFFICE PHILIP K. LINDSAY, OF SOMERVILLE,MASSACHUSETTS COMPRESSOR OR THE LIKE Application filed November 17,1927. Serial No. 233,927.

This invention pertains to pumping, coinpressing, or similar apparatusand has for its principal object the provision of apparatus of this typewhich is of very compact form and li ht weight, and which can beconstructed quickly and at low cost by the employment of units which areof substantially standard type. I have herein selected a portable aircompressor as illustrative of one desirable embodiment of my invention,but with the understanding that in its broader aspects the invention isof more general application.

Small portable air compressors, such as are now commonly used fordriving compressed air tools, applying liquid sprays or abrasive blasts,etc. as well as other devices having reciprocating parts, are nowcommonly driven by means of internal combustion engines. Usually a beltor chain drive is employed, the engine and compressor units beingdisposed in spaced relationship upon a wheeled platform or othersuitable support. Such an arrangement occupies a considerable space;both the engine and compressor unit must be complete in itself; and theassemblage is heavy and difficult to move. In accordance with thepresent invention I take advantage of the general similarity instructure and mode of operation of the engine and com pressor units andgreatly simplify and cheapen the combined apparatus by mounting theengine and compressor cylinders upon the same crank case, directlydriving the compressor piston from the engine piston. In this way theapparatus may be made in very compact form and of decreased weight ascompared with the assemblage of separate units commonly employed.

40 Since it is cheaper to employ an engine unit of substantiallystandard type than it would be to build the entire engine in therelatively small quantities required for this particular purpose, Iprovide for a very slight modification of the standard engine, such asmay without difficulty and with little additional expense be made by themanufacturer of the standard engine, and when thus modified theassembled engine may be employed for gen oral purposes, if desired, orquickly connected (without disassembling it) to an air compressor orother unit for directly driving the latter.

In the accompanying drawings I have illustrated a standard type ofengine, modified in accordance with my present invention, and have alsoshown the same engine associated with a compress r unit.

In the drawings,

Fig. 1 is a fragmentary side elevation of a one cylinder internalcombustion engine of standard type but modified in accordance with thepresent invention, the usual accessory parts being omitted;

Fig. 2 is a fragmentary vertical section on the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary side elevation, to somewhat larger scale,illustrating the modified connecting rod forming a part of my presentinvention;

Fig. 4 is an elevation illustrating a removable cover plate forming adesirable feature of the invention;

Fig. 5 is a side elevation of a secondar connecting rod adapted to beattached to the connecting rod shown in Fig. 3 when the engine is to beused for direct driving of a reciprocating part; Fig. 5 is a fragmentaryelevation showmg the upper part of the connecting rod of Fig. 5 viewedfrom the left-hand side of the latter figure;

Fig. 6 is a composite view showing in side and end elevation a wrist pinfor uniting the secondary connecting rod to the main rod;

Fig. 7 is an elevation illustrating a gasket adapted to be interposedbetween the crank case of the engine and an air compressor cylinderattached thereto; and

Fig. 8 is a vertical section substantially on the same plane as Fig. 2,but showing the engine having an air compressor cylinder associatedtherewith.

The engine unit here disclosed is of internal combustion type andcomprises the power or drive cylinder 1 mounted upon the crank case 2.This crank case is of closed type and is here shown as having theintegral bottom 8, although a bottom of other type may be employed. Asillustrated the engine employs the splash system of lubrication in whichthe crank case normally contains a considerable amount of lubricant.

The engine has a crank shaft 4 provided with a crank having the crankpin 5. A trunk piston (5 reciprocates in the cylinder 1 and is providedwith a wrist pin 7 to which the upper end of the main connecting rod 8is secured. The lower end of this connecting rod 8 is provided with ajournal opening 9 (Fig. 3) for the reception of the crank pin 5.

In accordance with this invention the connecting rod 8, which in otherrespects may be of usual construction, is provided with an outstandingboss 10 near its lower end. This boss is furnished with a transverseopening 11 and is preferably split at 12 and furnished with one or morebolts 13 so that a wrist pin or other connecting element, hereinafterdescribed, may be clamped within the opening 11. v

The crank case 2 has one side wall 141 which is provided with asubstantially vertical and flat outer surface 15. The wall 14 isprovided with a vertically elongate slot 16 in the vertical plane ofmovement of the crank-pin 5, and is also furnished with a plurality ofscrew-threaded openings 17. The openings 17 are adapted to receive bolts18 for securing a removable cover 19against the face 15 If desired agasket 20 may be interposed between the cover 19 and the face 15 so asto provide a tight oint through which oil will not leak. The face 15 ofthe crank case is substantially parallel to the axis of the crank shaft4 and the wall 1d of the crank case having this outer flat surface 15 ispreferably at that side of the crank case at which the crank movesdownwardly.

The engine thus constructed may be manufactured by makers of standardengines and may be sold as a standard engine and used for ordinarypurposes but it is easily assembled with an air compressor cylinder fordirect driving of the compressor piston without taking down the engine.

Referring to Figs. 5 to 8 inclusive, a secondary connecting rod isindicated at 21, such connecting rod being forked at the end to providea slot 22 and having a transverse opening 23 at such end for thereception of a wrist pin 24 (Fig. (3). This wrist pin is of. a sizeadapted to fit in the opening 11 of the main connecting rod 8 and may befurnished with slots 25 or other elements for cooperation with a specialtool or fixture by means of which it may be introduced into the opening11.

In uniting the secondary connection rod 21 to the main rod it is simplynecessary to remove the cover plate 19 and pass the end 22 of thesecondary connecting rod through the slot 18 into the crank case of theengine, fitting the slot 22 in its end 22 over the boss 10 on the mainconnecting rod 8. By means of the special tool above referred to thewristpin 24': is also introduced through the slot 16 and is passedthrough the aligned openings 23 and 11. The bolt or bolts 13 are nowtightened, thus securely clamping the wrist pin in the opening 11 andpivotally uniting the secondary connecting rod to the rod 8.

The slot 16 is preferably of a minimum width sufficient to permit thesmallest dimension of the end 22 the secondary connecting rod 21 to bepassed through it, such narrow slot beingodesirable in order to avoidexcess delivery of the lubricating material from the crank caseoutwardly through the slot. For the same reason it is desirable, asalready pointed out, to have this slot at that side of the crank case atwhich the crank moves downwardly so that the lubricating medium will notbe splashed or thrown violently through the slot.

If desired a gasket 30 such as shown in Fig. 7 may now be slipped overthe connecting rod 21, such gasket usually being of flexible orresilient material and having a narrow elongate slot 31 which may be ofa width substan tially equal to the central or web portion of theconnecting rod 21. This gasket is also provided with openings 31corresponding to the openings 17 in the wall 14 of the crank case.

A trunk piston 28 of usual type is new connected to the free end of theconnecting rod 21 by means of a wrist pin 29 passing through a suitableopening 26 in the connecting rod. This piston 28 is slipped into thecylinder 27 of the air compressor and the cylinder is sccured to thecrank case 2 by means of bolts or rods entering the openings 17. Theparts new occupy the position shown in F ig. 8

where the piston 28 of the air compressor unit I is directly connectedto the engine unit. As above noted, this assembly of the parts isaccomplished without taking down the engine or in any way disturbing orinterfering with the normal position of the engine parts or itsaccessories. Obviously, by a relatively slight modification, thesecondary connecting rod might be secured directly to the crank pinrather than to the main rod.

The auxiliary parts of the compressor may now be assembled in place andthe apparatus completed, it being noted that the same crank caseconstitutes a base for both engine and air compressor, thus making avery considerable saving in weight, material and space, all of which arehighly important in small portable devices of this type where it isnecessary to provide a compact structure which may readily be moved fromplace to place and which may be sold at a low price. Moreover, the easeof assembly of the compressor or other driven unit with the enginepermits the manufacture, on relatively small. scale, of portable aircompressors and the like so that they may be sold in competition withdevices of similar character made in great quantities upon a productionbases, since it permits the builder to employ standards parts withoutrequiring disassembly of such parts to permit the driving and drivenunits to be associated.

While I have herein illustrated certain desirable details ofconstruction it is to be un derstood that the invention is notnecessarily limited to these exact details, except as delined by theappended claims, and that while the invention has been illustrated asapplied to air compressor apparatus, it is of broader utility and may befound valuable wherever a reciprocating part is to be driven directlyfrom the crank shaft of an engine of the type herein disclosed.

I claim:

1. Apparatus of the class described having a power cylinder, a piston inthe cylinder, a crank shaft provided with a crank and crankpin, and acrank case, said apparatus comprising a connecting rod having a journalopening for the reception of the crank pin, said connecting rod havingan opening adj acent to said journal opening for the reception of meansfor uniting a secondary connecting rod to the main rod, the crank casehaving a slot in the plane of movement of the main rod, and a removablecover normally closing said slot.

2. Apparatus of the class described having a power cylinder, a piston inthe cylinder, a crank shaft provided with a crank and crankpin, and acrank case, said apparatus comprising a connecting rod having a journal.opening for the reception of the crank pin,

said connecting rod having means pivotally uniting a secondaryconnecting rod thereto, the crank case having a substantially flat outerface, and means for alternatively clamping a cover plate or a compressercylinder against said flat face, the flat face of the crank case havingan opening through which a secondary connecting rod may pass.

3. Apparatus of the class described having a power cylinder, a piston inthe cylinder, a crank shaft provided with a crank and crankpin, and acrank case, said apparatus comprising a connecting rod having a journalopening for the reception of the crank-pin, the crank case being ofclosed type adapted to contain oil for splash lubrication, the mainconnecting rod having provision for uniting a secondary connecting rodthereto, the crank case having an opening in its wall through which asecondary connecting rod may be introduced and united to the main rodwhile the engine parts are in assembled relation, and a removable covernormally closing said opening.

4. Apparatus of the class described having a power cylinder, a piston inthe cylinder, a crank shaft provided with a crank and crankpin, and acrank case, said apparatus comprising a connecting rod having a journalopening for the reception of the crank-pin, said connecting rod having atransverse opening for the reception of a wrist pin adapted to unite asecondary connecting rod to the main rod, the crank case having asubstantially fiat outer face parallel to the axis of the crank shaftand at that side of the case at which the crank-pin moves downwardly,said flat face having a vertical slot substantially in the plane ofrotation of the crank pin, said slot being of a width just suflicient topermit the passage of a secondary connecting rod therethrough.

5. Apparatus of the class described having a power cylinder, a piston inthe cylinder, a crank shaft provided with a crank and crankpin, and acrank case, said apparatus comprising a connecting rod having a journalopening for the reception of the crank-pin, said connecting rod having aprojecting boss at a point adjacent to the crank-pin receiving opening,said boss having a transverse opening therethrough, means for securing awrist pin in the opening in the boss, the crank case having a verticalwall substantially perpendicular to the plane of rotation of thecrankpin, said wall having a slot therethrough to permit a. secondaryconnecting rod to be connected to the main connecting rod withoutdisassembling the engine, and means for alternatively attaching a coverplate or a compressor cylinder to said vertical wall.

6. Apparatus of the class described having a power cylinder, a piston inthe cylinder, a crank shaft provided with a crank and crankpin and acrank case, said apparatus comprising a connecting rod having a journalopening for the reception of the crank-pin, said connecting rod having aprojecting boss provided with a transverse opening whose axis isparallel to the axis of the crank shaft, the boss being split andprovided with means for clamping a wrist pin in said transverse opening,the crank case having a slot in its side Wall of a width substantiallyjust sulficient to permit entry of a secondary connecting rod and theunion of said secondary rod with the first rod by means of a wrist pindisposed in said transverse opening, the slotted wall of the crank casehaving an outer surface finished to receive the end of a secondarycylinder.

Signed by me at Boston, Mass, this fourteenth day of November, 1927.

PHILIP K. LINDSAY.

